Combining fonts is an art rather than a science, but there are basics that will help you make decisions. Typography.com has some ideas. (Not to be confused with my blog post Font-Pairs Font Friday, which suggests five websites for AI-generated two-font pairings.)
Four Techniques for Combining Fonts
Building a palette is an intuitive process, and expanding a typographic duet to three, four, or even five voices can be daunting. Our approach for mixing font families is to keep one quality consistent, and let the others vary.